ノンジンクアマルガム、銅アマルガムおよびその混合合金の各種試験成績について

概要

論文の詳細を見る
At the two laboratories (Shofu Dental Laboratory and G. C.'s Chemical Manufacturing Company), we have made 3 series of investigation, and the results obtained were summarized as follows : 1) The setting time of the copper amalgam specimens was 145.3 minutes on an average with the hand pressure of 3 kilograms and final hand pressure of 3 kilograms, as shown in Table 3. The setting time of the copper amalgam specimens with the hand pressure of 3-8 kilograms, was 129.5 minutes on an average. The compressive strength of specimens obtained under these two different conditions was respectively 1001kg/cm^2 in the former condition, and 1610kg/cm^2 in the latter condition. 2) The setting times and the duration of plasticity with the hand pressure of 3 kilograms and final hand pressure of 3 kilograms for G. C.'s non-zinc-amalgam and their cobined alloys of copper amalgam were obtained respectively as 10.5 minutes and 5.5 minutes for No.1 specimen, 10.0 minutes and 9.0 minutes for No.3 specimens, 8.5 minutes and 8.0 minutes for No.4, as shown in Table 3. 3) The setting time and the duration of plasticity of test specimens with the hand pressure of 3 kilograms and final hand pressure of 8 kilograms for "Pre-non-zina amalgam" and their combined alloys of copper amalgam are obtained with the use of the mechanical amalgamator and the hand mortor and pestle, and the results were shown in Table 4. 4) The setting times of "Pre-non-zinc amalgam" and their combined alloys of copper amalgam obtained by the use of the mechanical amalgamators, were slightly accelerated than those obtained by the use of hand mortar and pestle. 5) The setting time and the duration of plasticity of G. C.'s non zine amalgam specimens with the hand pressure of 3-8 kilograms is illustrated in Table 5. In view of our results, it seems that the proper specimens to be selected for clinical dental use for their ideal dimensional change may be reprsented by no. 1-A, C, D, as listed iu Table 5. 6) As shown in Table 5 and 6, there was no appreciable correlation between alloy-copper ratios and setting times, in contrast to the copper amalgam, where the greater the alloy-copper ratios, the longer the setting times. In order to extend the duration of plasticity further than 8 minutes and to raise the compressive strength above 4100 kilograms per square centimeter, the alloy-copper ratios should be increased to above 6.0 per cent in a single specimen. 7) The flow rates of No.1 to 4 alloys were within the limits of JIS (Japan Industrial Standards) as shown in Table 3. 8) The dimensional changes with hardening were least in No.2 alloys, followed by No.4, No.3 and No.1 alloys in this order as shown in Table 3 and Table 4. 9) The porosities of the copper amalgam alloys are markedly larger and fewer than are observed with other alloys. This would probably be caused by the greater viscosity of the alloy, which tends to trap the air bubbles very firmly within the alloy during manipulation for mixing and filling the material. 10) The mixing times of non-zinc-amalgam alloys and their combined alloys with copper amalgam by mechanical amalgamator should be reduced to about 5 minutes to prevent an excessive contraction due to the over-mixing.
九州歯科学会の論文
1966-03-31

ノンジンクアマルガム、銅アマルガムおよびその混合合金の各種試験成績について

スポンサーリンク

概要

著者

関連論文

スポンサーリンク